There have been two open questions about Web 2.0 enhanced CoP (Community of Practice). The first one is the isolation of CoPs caused by the variety of web services, and the second one is the context loss in knowledge transference. Both of the questions arise from the discontinuity of the knowledge transference in a CoP or among CoPs. In order to tackle these questions, CAPK (Context, Actor, Pipe and Knowledge object), a new learning process model, is proposed to model learning in the Web 2.0 technology enhanced CoPs. In this model, the premise of learning is the connection to the knowledge objects by various pipes which can be used to maintain a connection with a knowledge object. Context is considered as the most important component of effective learning in this model. CAPK model can provide us a new perspective to tackle the above problems. In order to achieve effective learning in current web based CoPs, flexible connection to and management of knowledge objects are necessary to support learning in CoPs. Besides, a uniform context description is also a requirement. In this paper, after the introduction of the CAPK learning process model, we describe design and implementation of a prototype system for managing the pipes of knowledge objects to provide a solution to transfer context information through Activity Streams specification in and cross various systems.